Intertube burner



p 7, 1965 T. s. VOORHEIS ETAL 3,204,610

INTERTUBE BURNER 3 Sheets-Sheet 1 Filed July 9, 1963 INVENTORS VQORHEISHUDSON ERT F. BRUNS T ATTORNEYS Sept 1965 T. s. VOORHEIS ETAL 3,204,610

INTERTUBE BURNER 3 Sheets-Sheet 2 Filed July 9, 1963 INVENTORS PLE S.VOORHEIS IEL H. HUDSON ERT F. BRUNS ATTORN EYS Sept. 7, 1965 T. s.VOORHEIS ETAL INTERTUBE BURNER 3 Sheets-Sheet 3 Filed July 9, 1963ATTORNEYS United States Patent 3,204,610 INTERTUISE BURNER Temple S.Voorheis, Palo Alto, Daniel H. Hudson, San Lorenzo, and Robert F. Bruns,San Leandro, Califl, assignors to Coen Co., San Francisco, Calif., acorporation of California Filed July 9, 1963, Ser. No. 2%,752 9 Claims.(Cl. 122-235) This invention relates generally to the art of boilerfurnace construction and more specifically relates to that type ofconstruction known as intertube gas-fired boiler furnace system.

Until fairly recently, most industrial boilers that have been fired withgas or oil were arranged so that the burner introduced the fuel and airinto the furnace through a circular refractory throat or opening formedin the side of the furnace. In such a type of construction, it isnecessary to bendably deform or curve the boiler pipes around thecircular throat opening so as not to obstruct the emission of the fueland air directly into the furnace for ignition and combustion therein.It has been found that in many types of installations, it is a diflicultand expensive process to properly bend and curve the boiler pipes aroundthe refractory throat. As a consequence of this latter named difliculty,it has been proposed in more recent times, both in reference toconstructing new boiler installations as well as in converting oldboilers to the use of more modern and up-to-date burner equipment toform a rectangular opening in the furnace wall and to run the boilerwater tubes vertically across the opening in parallel spaced relation.

In this type of construction, it has been conventional practice to mounton the boiler tubes that span the furnace opening gas jets which operateto emit jets of gas into the furnace proper in conjunction with airintroduced simultaneously from a windbox or blower through the spacesdefined between the spaced apart boiler tubes. The gas jets that aremounted on the boiler tubes are commonly referred to in the art as gasshoes. In effect, each gas shoe consists of a hollow vertical manifoldtube that is mechanically mounted to the boiler tubes which manifoldtube is provided with a series of gas jet openings displaced andoriented in such way as to inject streams of raw gas or other fuel atdesired angles of emission into the furnace in such manner as toimpringe upon and be entrained by the streams of air flowing through thespaces between the boiler tubes. At the point where the gas streams andair mix, combustion occurs within the boiler. Although this type ofintertube gas burner system as developed to date permits the boilertubes to span the openings into the furnace and thereby eliminates thenecessity of bending or curving the tubes around a circular throatopening, such system has been found to involve certain otherdifficulties and problems which the present invention is specificallydesigned to alleviate or minimize.

More specifically, in the conventional type of intertube gas-firedsystem above mentioned, all of the air that flows through the verticalpassages defined by the spacings between the boiler pipes is moving in astraight line path parallel to the longitudinal axis of the furnace.There is no provision for swirling or distributing the air or impartingto it any other vector of movement other than its straight line path offlow from one end of the furnace to the other. When the air stream mixeswith the gas and combustion occurs, the expansion of the gas caused bythe heat and combustion added to the velocity of the incoming airresults in a high temperature velocity movement of burning gasesimpinging upon a concentrated area on the opposite side of the boiler.This in turn results in an uneven concentration of heat in the boilerPatented Sept. 7, 1965 furnace and, at the end where the heatconcentration is highest, the boiler tubes may be subjected to abnormaldestructive forces.

The particular embodiment of the present invention which is shown in thedrawings and which will be described more fully hereinafter comprises incombination with a rectangular furnace opening a plurality of spacedapart parallel boiler tubes spanning said opening; the spaces betweensaid tubes defining vertical passages for flow of combustion air intosaid furnace; gas jet means mounted adjacent at least some of the tubesfor emitting jets of gas into said chamber at an angle intersecting theair flowing through said passages; air deflector means mounted in atleast some of said passages; said air dcflector means in each passagecomprising a plurality of air vanes mounted at varying angles inreference to horizontal to direct components of the air stream atvarious angles. The flame pattern is thus distributed uniformly over theinterior of the boiler; consequently, the longevity of the boiler tubesand refractory lining is increased, and heat absorption by the boilertubes in the furnace is more uniform.

A feature and advantage of the present invention resides in orientingthe vanes in one intertube space so that air is directed generallyupwardly while the vanes in intertube spaces on either side of the firstnamed space are oriented to direct the air generally downwardly, therebyto provide a scrubbing action between air streams entering throughadjacent intertube spaces. As a consequence of such scrubbing action,turbulence occurs to intermix intimately air and fuel.

The objects, features and advantage of this invention will be apparentupon referring to the following specification and attached drawings inwhich:

FIGURE 1 is a cross-sectional plan view showing my improved intertubeburner mounted on a water tube boiler;

FIGURE 2 is an enlarged cross-sectional elevation view of an airdistributor of my invention taken substantially along line 2 2 of FIGURE1;

FIGURE 3 is an enlarged front view of my air distributor takensubstantially along line 33 of FIGURE 1;

FIGURE 4 is a cross-sectional view of a modification of my airdistributor;

FIGURE 5 is a schematic representation of a flame pattern in a typicalwater tube boiler;

FIGURE 6 is a schematic representation of a flame pattern produced byuse of the prensent invention; and

FIGURE 7 is a cross-sectional view of a. fuel manifold of the presentinvention.

Referring more particularly to the drawings, reference numeral 12indicates a refractory lining of a conventional water tube boiler 13which lining is structurally supported by an outer shell 14. Alongtheinterior surface of refr-actory lining 12 is disposed a plurality ofwater tubes 16 that extend in a conventional manner along the interiorboiler wall. Water is fed through water tubes 15 from a source not shownand heat applied to the exterior surface of the water tubes converts thewater therein to steam.

Boiler 13 is provided with an opening 18 in a side wall thereof throughrefractory lining 12 and shell 14 which opening communicates with theboiler interior. Although opening 18 can be any convenient shape,provision of a rectangular opening makes easier the construction andinstallation of the burner. It is to be understood that opening 18 canbe provided in the boiler wall when the boiler is initially constructedor that it can be cut in the wall at any later time, such as duringrepair. Extending from the sides of opening 18 are support members 20that support on their outer ends a conventional air duct 22 into whichair is moved from a conventional fan or blower shown schematically at24. Duct 22 substantially covers the entire opening 18 to permitmovement of air into the furnace throughout the entire area of theopening.

Water tubes 16 span opening 18 in parallel spaced apart relation and, inaccordance with conventional water tube boiler technology, are alignedvertically. For convenience of description the spanning water tubes aredivided into two alternate groups; tubes 16a forming one group, andtubes 16b forming the other group. Each water tube 16a has associatedtherewith a fuel manifold or show 26 which extends substantiallythroughout the entire span of a tube 16a and is provided with an arcuateconcavity 28 that nests with the exterior surface of water tubes 16a.Each manifold 26 has a hollow interior forming one or more fuel conduits30 therein. Adjacent concave portion 28 the manifold is provided withbackwardly sloping walls 32 which have formed therein a plurality of jetopenings 34 for injecting fuel into the boiler interior through spacesbetween adjacent water tubes. Attached to each manifold 26 in fluidcommunication with conduits 30 is a pipe 36 that is connected to asuitable fuel header, not shown, for effecting delivery of fuel to jetopenings 34. Each side extremity of manifold 26 is provided with amounting flange 37 and with two or more openings 38 for receiving amounting bolt 39 which is welded, or otherwise suitably affixed, towater tube 16a.

Each tube 16a adjacent the side edges of opening 18 is provided with amanifold 30' having only one row of fuel jets 34' as well as only onemounting flange 37'. On the opposite side of manifold 30 is a protrusion40 that is received by a ridge 42 formed in opening 18.

To each tube 16b, between tubes 16a with which manifolds 26 areassociated, is attached an air distributor indicated generally at 44.Air distributor 4d (FIGURE 3) has an elongate central portion 46 whichdefines several mounting holes 48. A threaded fastener 50 extendsthrough mounting holes 48 into a suitable clamp 52 that is aflixed toeach alternate water tube 16b. Extending outwardly from opposite sidesof central portion 46 are vane assemblies 53a and 53b each of which hasa plurality of vanes 54. Vanes 54 are adapted at their outer extremities55 to bear against mounting flanges 37 so as to aid in securingmanifolds 26 in nesting relationship with water tubes 16a. Each vaneassembly 53a, 53b is formed on the inner edge thereof with aperturedflanges 56 to effect attachment to central portion 46.

Each vane 54 is formed with a generally flat upper surface 57 and agenerally flat lower surface 53. Opposing surfaces of adjacent vanes aresubstantially parallel with one another. Between the upper surface 57 ofone vane, for example vane 54a of FIGURE 2, and the lowe surface of thevane thereabove, for example vane 54b of FIGURE 2, an air passage 60 isformed. Because vane assemblies 53a and 53b of the specific airdistributor of FIGURES 2 and 3 are oppositely mounted on central portion46, the device is particularly suitable for installation in an opening18 that is positioned near the vertical center of the boiler wall. Theair moving through distributor 4,4 is distributed upwardly by vaneassembly 53a and downwardly by vane assembly 53b. The air streams willalso diverge horizontally in the furnace interior as a consequence ofwhich the upwardly moving stream through vane assembly 53a willencounter the downwardly moving stream through vane assembly 5312. Suchencounter creates a scrubbing action between the two streams as a resultof which substantial turbulence occurs. Turbulent air flow promotesadmixture of air with fuel injected from fuel jets 34.

In such installation the lowermost air passage 6% of vane assembly 53aand the uppermost air passage 60a of vane assembly 53b are generallynormal to the plane defined by water tubes 16a16b, and each successiveair passage above lower passage 60a and below passage 6% is inclined ata decreasing angle relative to the water tube plane. By way of examplein one installation of the present invention air passage 60b is alignedat an angle of approximately relative to the plane of the water tubes16a and air passage 66c adjacent and above air passage 60b is aligned atan angle of 66 relative to the water tube plane. Air passages belowpassage 6% are aligned at angles progressively greater than 70, airpassages above passage 600 are aligned at angles progressively smallerthan 66. It will be obvious that such alignment of air passages dill)and 60c is obtained by a corresponding angular position of the opposingvane surfaces forming the respective air passages. The angular positionof each air passage 60 is progressively reduced until at the top of vaneassembly 53:: on air distributor 44 an air passage 60d is aligned at anangle of about 30 relative to the plane of the water tubes. It is to beunderstood that the specific angular values given above are exemplary,and that different angular values can be provided to suit individualburner installations. Additionally, the vane assembly can both bemounted to direct moving air upwardly or to direct the air downwardly.

In operation fuel is supplied through pipes 36 to conduits 3%) inmanifolds 26; the fuel is thus injected into the boiler furnace interiorthrough fuel jet openings 34. Actuation of blower 24 moves air throughduct 22 into the boiler furnace interior through spaces between adjacentspanning water tubes. The direction of movement is indicated by an arrow62 in FIGURE 2. As the moving air impinges upon the upper surfaces 57 ofvanes 54 in vane assembly 53a, the air is deflected upwardly by amountsproportional to the angular alignment of air passages 60. Air movingthrough vane assembly 53b is directed downwardly. Moving air sodistributed will entrain fuel ejected from jet openings 34 and uponignition, by suitable means not shown, a uniform flame pattern such asdepicted in FIGURE 6 will result. As contrasted with the flame patternshown in FIGURE 5, which is the flame pattern obtained withoutinterposition of air distributors 44 in the intertube spaces, the flamepattern afforded by the present invention is superior, in that moreuniform heat distribution is obtained and concentrations of heat onrefractory linings 12 or boiler tubes on the opposite furnace side wallare eliminated.

A modification of the present invention particularly suitable forinstallations wherein a boiler wall opening is formed intermediate thevertical extremities of the wall is shown in FIGURE 4. An air deflector70 is shown having a vane 73 intermediate the ends thereof that has anupper surface 74 and a lower surface 76 that are generally normal to theplane in which the water tubes reside. In parallel opposition with uppersurface 74 a lower surface 76a of a vane 73a is provided to form an airpassage 80. In parallel opposition with lower surface 76 and uppersurface 74b of a vane 73b is provided to form an air passage 80b.Successive air passages 80 formed above and below vane 73 are aligned atprogressively decreasing angles with respect to the water tube plane.

The operation of a burner provided with modified air deflector 7G issubstantially identical with the mode of operation described above. Airmoving through the deflector in a direction indicated by arrow 82 isdeflected by the lower surfaces of the vanes below vane 73 and by theupper surfaces of the vanes above vane 73. Air thus deflected will forma uniform flame pattern having the advantages referred to above.

While two embodiments of the invention have been shown and described, itwill be apparent that other adaptations and modifications can be madewithout departing from the true scope of the invention.

What is claimed is:

1. In a water tube boiler furnace of the type having a fiat wall withparallel spaced apart water tubes extending along the wall interior ofthe boiler furnace, an improved intertube burner comprising: a portionof said wall forming an opening therethrough communicating with theinterior of the boiler furnace, a plurality of parallel spaced apartWater tube-s spanning said opening; a gas manifold associated with eachalternate tube, said manifold having a hollow central portion and beingformed with a plurality of jet openings in fuel communication with thehollow portion, said jet openings being formed on opposite sides of saidtube and being adapted to inject fuel between adjacent tubes into theboiler furnace interior, an air deflector associated with each alternatetube, said air deflectors having a plurality of vanes disposed in an airflow path between adjacent tubes, said vanes being angularly orientedrelative one another and relative the longitudinal axis of said tubes toeifect uniform air distribution obliquely with respect to perpendicularof the longitudinal axis of the tubes and throughout the boiler furnaceinterior.

2. In a water tube boiler furnace of the type having a Wall formed withan opening, a plurality of parallel spaced apart tubes spanning saidopening, a plurality of jets for injecting fuel to the interior of saidboiler furnace through spaces between said tubes, and means for movingair into the interior of said boiler through spaces between said tubes;means for distributing the moving air comprising: an elongate centralportion, means for mounting said central portion onto one of said tubeslongitudinally thereof, a plurality of fixed vanes extending from saidcentral portion into the intertube space, each said vane having firstand second flat surfaces, said surfaces being aligned so that the secondsurface of one vane is disposed substantially parallel with thefirst surface of the vane adjacent thereto, each pair of said parallel vanesurfaces defining a dilferent angle relative to the direction of airmovement through said wall opening so that a uniform flame pattern isestablished in the boiler.

3. In a water tube boiler of the type having a wall defining an openingand a plurality of parallel spaced apart Water tubes spanning saidopening, alternate said tubes forming first and second tube groups, animproved burner for said boiler comprising a plurality of elongate fuelmanifolds each being formed with a concavity for nesting relation with atube in said first tube group, means for securing each said manifold tothe tube related thereto, each said manifold having a plurality of jetsfor injecting fuel into said boiler through spaces between adjacenttubes, means disposed between spaces between adjacent tubes fordistributing air moving through said wall opening, and means formounting said air distributing means to the tubes of said second tubegroup, said air distributing means having an elongate central portion, aplurality of vanes fixedly secured to said central portion fordeflecting the moving air from a straight line path and obliquely withrespect to perpendicular of the longitudinal axis of the tubes, saidvanes extending from said central portion to said manifold.

4. In combination with a boiler furnace of the class that includes avertical wall formed with a burner opening therein and a plurality ofco-planar parallel spaced apart Water tubes vertically spanning saidopening, an improved air distributor comprising an elongate centralportion, means for mounting said central portion to one of said watertubes, a plurality of vanes fixedly extending from opposite sides ofsaid central portion into spaces between adjacent Water tubes, adjacentsaid vanes having mutually opposing surfaces forming air passages intothe interior of said boiler furnace, said vane surfaces being orientedso that each said air passage is formed at a different angle relative tothe plane of said Water tubes for distributing lowest said air passageis formed generally normal to the plane of said water tubes and eachsucceeding air passage is formed at a successively smaller upwardlyinclined angle relative said plane.

6. An air distributor according to claim 4 wherein two adjacent airpassages intermediate the ends of said central portion are disposedgenerally normal to the plane of said water tubes, each air passageabove said adjacent air passages is formed at a successively smallerupwardly inclined angle relative said plane and each air passage belowsaid adjacent air passages is formed at a successively smallerdownwardly inclined angle relative said plane.

7. An air distributor according to claim 4 wherein the lowest said airpassage formed on one side of said central portion is oriented generallynormal to the plane of said water tubes and each succeeding air passageis formed at a successively smaller upwardly inclined angle relativesaid plane, and wherein the highest said air passage formed on the otherside of said central portion is oriented generally normal to the planeof said water tubes and each succeeding air passage is formed at asuccessively smaller downwardly inclined angle relative said plane,whereby air entering opposite sides of said central portion is deflectedupwardly and downwardly respectively, thereby to afford scrubbing actionbetween the two deflected air streams.

8. In combination with a boiler furnace of the class that includes avertical Wall having a burner opening therein and a plurality ofco-planar parallel spaced apart water tubes vertically spanning saidopening, an improved air distributor comprising an elongate centralportion, means for mounting said central portion to one of said watertubes, a plurality of vanes fixedly extending from opposite sides ofsaid central portion into spaces between adjacent water tubes, each saidvane having an upper and a lower surface, the upper surface of one vanebeing in confronting relation to the lower surface of the vane adjacentthereto, a surface of the said vane at a vertical extremity of saidopening and the confronting surface of the adjacent vane beingsubstantially normal to the plane of said spanning tubes, eachconfronting pair of surfaces vertically inwardly of said extreme vanebeing disposed at a decreasing angle relative said plane, w ereby airmoving through said air distributing means is uniformly distributedWithin said boiler furnace.

9. In combination with a boiler of the class that includes a verticalwall having a burner opening therein and a plurality of co-planarparallel spaced apart water tubes vertcially spanning said opening, animproved air distributor comprising an elongate central portion, meansfor mounting said central portion to one of said water tubes, aplurality of vanes fixedly extending from opposite sides of said centraltubes, one of said vanes intermediate the ends of said central portionbeing formed with an upper and a lower surface generally normal to theplane of said water tube, the vane next above said intermediate vanehaving a lower surface in substantial parallel opposition to the uppersurface of said intermediate vane, the vane next above said intermediatevane having an upper surface at an upwardly sloping angle relative theplane of said water tubes, each succeeding vane having a lower surfacein parallel opposition to the upper surface of the vane therebelow andan upper surface at an upwardly sloping angle relative the plane of saidWater tubes less the angle of the lower surface thereof; the vane nextbelow said intermediate vane having an upper surface in substantialparallel opposition to the lower surface of said intermediate vane, thevane next below said intermediate vane having a lower surface at adownwardly sloping angle relative the plane of said water tubes, eachsucceeding vane havportion into spaces between adjacent Water 7 ing anupper surface in parallel opposition to the lower surface of the vanethereabove and a lower surface at a downwardly sloping angle relativethe plane of said water tubes less the angle of the upper surfacethereof, whereby air moving into said boiler through said distributor isdistributed upwardly by the vanes above said intermediate vane and isdistributed downwardly by the vanes below said intermediate vane.

References Cited by the Examiner UNITED STATES PATENTS 2,229,068 1/41Frisch 222--23S 3 Leach 122235 Reed 122-235 Smith et a1. 122-235 Barton122-235 Examiners.

1. IN A WATER TUBE BOILER FURNACE OF THE TYPE HAVING A FLAT WALL WITHPARALLEL SPACED APART WATER TUBES EXTENDING ALONG THE WALL INTERIOR OFTHE BOILER FURNACE, AN IMPROVED INTERTUBE BURNER COMPRISING: A PORTIONOF SAID WALL FORMING AN OPENING THERETHROUGH COMMUNICATINGWITH THEINTERIOR OF THE BOILER FURNACE, A PLURALITY OF PARALLEL SPACED APARTWATER TUBES SPANNING SAID OPENING; A GAS MANIFOLD ASSOCIATED WITH EACHALTERNATE TUBE, SAID MANIFOLD HAVING A HOLLOW CENTRAL PORTION AND BEINGFORMED WITH A PLURALITY OF JET OPENINGS IN FUEL COMMUNICATION WITH THEHOLLOW PORTION, SAID JET OPENINGS BEING FORMED ON OPPOSITE SIDES OF SAIDTUBE AND BEING ADAPTED TO INJECT FUEL BETWEEN ADJACENT TUBES INTO THEBOILER FURNACE INTERIOR, AN AIR DEFLECTOR ASSOCIATED WITH EACH ALTERNATETUBE, SAID AIR DEFLECTORS HAVING A PLURALITY OF VANES DISPOSED IN AN AIRFLOW PATH BETWEEN ADJACENT TUBES, SAID VANES BEING ANGULARLY ORIENTEDRELATIVE ONE ANOTHER AND RELATIVE THE LONGITUDINAL AXIS OF SAID TUBES TOEFFECT UNIFORM AIR DISTRIBUTION OBLIQUELY WITH RESPECT TO PERPENDICULAROF THE LONGITUDINAL AXIS OF THE TUBES AND THROUGHOUT THE BOILER FURNACEINTERIOR.